The present disclosure relates to a vehicle that switches between, for example, front wheel drive, rear wheel drive, and all wheel drive, and to a control method thereof.
It is known to provide a drive method of a vehicle having an engine that drives from wheels and motors that drive rear wheels (auxiliary drive wheels). In such method, execution of positive drive is prohibited when lateral G (i.e. lateral acceleration) exceeds a predetermined value, as it is preferable to leave attitude control of a vehicle to a steering wheel operation by a driver. “Positive drive” mentioned in related art refers to drive auxiliary and is defined as an antonym of braking as “reverse drive”. Moreover, from the perspective that improving stability of a vehicle in four wheel drive is preferred, positive drive can be forcibly executed in independent mode.
Further, a four wheel drive vehicle has been proposed that can separately and independently drive front wheels and rear wheels. In such vehicle, front wheels are driven by a drive unit in which an internal combustion engine and an electric motor are arranged in-line, and rear wheels are driven by electric motors.
As described in the related art discussed above, front wheels are the main drive wheels that are driven by the engine and the rear wheels are auxiliary drive wheels driven by the motors. In other words, a vehicle according to one known embodiment can provide front wheel drive by the engine alone or four wheel drive by the engine and motors, but rear wheel drive by the motors alone is not addressed. Further, a study has not been provided concerning what specific value should be given to the predetermined value for lateral G.
In light of the problems described above, an aspect of the present disclosure is to provide a vehicle in which a drive state can be favorably selected in a configuration that separately and independently drives front wheels and rear wheels and to provide a method for controlling the vehicle.